As they waited for play to resume following a third-quarter timeout Sunday at Staples Center, Shaquille O’Neal and Kurt Thomas stood next to each other in the lane, the Knicks ready to inbound the ball.

O’Neal leaned over and whispered something in Thomas’ ear. He wasn’t inviting Thomas to his birthday party that evening. Both centers had alternately abused each other on the offensive end, the 330-pound Shaq easily muscling inside and scoring on little shots from the low post, while the skinnier Thomas rained jumpers from medium range.

“He was telling me to stop shooting those jumpers,” Thomas said. “But it was part of the game plan.”

O’Neal was tired of coming out to guard Thomas, who put a stamp on his NBA Player-of-the-Week performance with 20 points and 12 rebounds.

Thomas has frustrated plenty of opposing centers since Marcus Camby went down with a likely season-ending hip injury Feb. 1. Thomas is only 6-9, 235 pounds but his versatility in his new role as a pivot man makes him more dangerous. Bigger, slower centers don’t enjoy coming out and defending Thomas’ medium-range jumper that has been golden recently.

In the 17 games since Camby went down, Thomas switched from power forward to center and has averaged 16 points and 8.4 rebounds. According to research done by Knicks P.R. whiz staffer KeJuan Wilkins, Thomas has gone up against opposing starting centers who on average are three inches taller and 22.6 pounds heavier.

Last night, Thomas faced 7-2, 261-pound Dikembe Mutombo, whom GM Scott Layden had envisioned as the successor to Patrick Ewing. No matter what Thomas does in the pivot, he seems to be underappreciated as the club’s pursuit of a center in the draft and through trades is well-chronicled.

Yet Thomas, who won the weekly NBA award Monday by averaging 21 points and 3.8 rebounds across four games, has quietly been the Knicks’ best player since Jan. 1.

“We all appreciate him,” Don Chaney said. “We appreciate what he’s doing. He’s working his tail off on both ends of the floor. Everybody appreciates his value.”

It’s true that for the Knicks to be playoff-competitive Thomas needs a equally big and potent power forward or pivot to play alongside, but at least he’s held up to his part of the bargain.

Clarence Weatherspoon, though, has had a difficult time since Camby went down just when the Knicks needed the undersized power forward to step up and show he was worth using their $4.5 million exception last summer in a five-year, $27 million deal. In the 17 games without Camby, Spoon has averaged 8.3 points and 8.1 rebounds and shot just 40 percent – not the low double-double figures the Knicks had hoped he’d provide.

While Spoon challenged Karl Malone to a fight Friday in Utah, Thomas has been as quiet as a mouse with referees since the Texas trip when he blew his top in Houston in January and was ejected.